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Linux/arch/x86/platform/olpc/olpc-xo1-sci.c

  1 /*
  2  * Support for OLPC XO-1 System Control Interrupts (SCI)
  3  *
  4  * Copyright (C) 2010 One Laptop per Child
  5  * Copyright (C) 2006 Red Hat, Inc.
  6  * Copyright (C) 2006 Advanced Micro Devices, Inc.
  7  *
  8  * This program is free software; you can redistribute it and/or modify
  9  * it under the terms of the GNU General Public License as published by
 10  * the Free Software Foundation; either version 2 of the License, or
 11  * (at your option) any later version.
 12  */
 13 
 14 #include <linux/cs5535.h>
 15 #include <linux/device.h>
 16 #include <linux/gpio.h>
 17 #include <linux/input.h>
 18 #include <linux/interrupt.h>
 19 #include <linux/platform_device.h>
 20 #include <linux/pm.h>
 21 #include <linux/pm_wakeup.h>
 22 #include <linux/mfd/core.h>
 23 #include <linux/power_supply.h>
 24 #include <linux/suspend.h>
 25 #include <linux/workqueue.h>
 26 #include <linux/olpc-ec.h>
 27 
 28 #include <asm/io.h>
 29 #include <asm/msr.h>
 30 #include <asm/olpc.h>
 31 
 32 #define DRV_NAME        "olpc-xo1-sci"
 33 #define PFX             DRV_NAME ": "
 34 
 35 static unsigned long acpi_base;
 36 static struct input_dev *power_button_idev;
 37 static struct input_dev *ebook_switch_idev;
 38 static struct input_dev *lid_switch_idev;
 39 
 40 static int sci_irq;
 41 
 42 static bool lid_open;
 43 static bool lid_inverted;
 44 static int lid_wake_mode;
 45 
 46 enum lid_wake_modes {
 47         LID_WAKE_ALWAYS,
 48         LID_WAKE_OPEN,
 49         LID_WAKE_CLOSE,
 50 };
 51 
 52 static const char * const lid_wake_mode_names[] = {
 53         [LID_WAKE_ALWAYS] = "always",
 54         [LID_WAKE_OPEN] = "open",
 55         [LID_WAKE_CLOSE] = "close",
 56 };
 57 
 58 static void battery_status_changed(void)
 59 {
 60         struct power_supply *psy = power_supply_get_by_name("olpc-battery");
 61 
 62         if (psy) {
 63                 power_supply_changed(psy);
 64                 put_device(psy->dev);
 65         }
 66 }
 67 
 68 static void ac_status_changed(void)
 69 {
 70         struct power_supply *psy = power_supply_get_by_name("olpc-ac");
 71 
 72         if (psy) {
 73                 power_supply_changed(psy);
 74                 put_device(psy->dev);
 75         }
 76 }
 77 
 78 /* Report current ebook switch state through input layer */
 79 static void send_ebook_state(void)
 80 {
 81         unsigned char state;
 82 
 83         if (olpc_ec_cmd(EC_READ_EB_MODE, NULL, 0, &state, 1)) {
 84                 pr_err(PFX "failed to get ebook state\n");
 85                 return;
 86         }
 87 
 88         if (!!test_bit(SW_TABLET_MODE, ebook_switch_idev->sw) == state)
 89                 return; /* Nothing new to report. */
 90 
 91         input_report_switch(ebook_switch_idev, SW_TABLET_MODE, state);
 92         input_sync(ebook_switch_idev);
 93         pm_wakeup_event(&ebook_switch_idev->dev, 0);
 94 }
 95 
 96 static void flip_lid_inverter(void)
 97 {
 98         /* gpio is high; invert so we'll get l->h event interrupt */
 99         if (lid_inverted)
100                 cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
101         else
102                 cs5535_gpio_set(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
103         lid_inverted = !lid_inverted;
104 }
105 
106 static void detect_lid_state(void)
107 {
108         /*
109          * the edge detector hookup on the gpio inputs on the geode is
110          * odd, to say the least.  See http://dev.laptop.org/ticket/5703
111          * for details, but in a nutshell:  we don't use the edge
112          * detectors.  instead, we make use of an anomoly:  with the both
113          * edge detectors turned off, we still get an edge event on a
114          * positive edge transition.  to take advantage of this, we use the
115          * front-end inverter to ensure that that's the edge we're always
116          * going to see next.
117          */
118 
119         int state;
120 
121         state = cs5535_gpio_isset(OLPC_GPIO_LID, GPIO_READ_BACK);
122         lid_open = !state ^ !lid_inverted; /* x ^^ y */
123         if (!state)
124                 return;
125 
126         flip_lid_inverter();
127 }
128 
129 /* Report current lid switch state through input layer */
130 static void send_lid_state(void)
131 {
132         if (!!test_bit(SW_LID, lid_switch_idev->sw) == !lid_open)
133                 return; /* Nothing new to report. */
134 
135         input_report_switch(lid_switch_idev, SW_LID, !lid_open);
136         input_sync(lid_switch_idev);
137         pm_wakeup_event(&lid_switch_idev->dev, 0);
138 }
139 
140 static ssize_t lid_wake_mode_show(struct device *dev,
141                                   struct device_attribute *attr, char *buf)
142 {
143         const char *mode = lid_wake_mode_names[lid_wake_mode];
144         return sprintf(buf, "%s\n", mode);
145 }
146 static ssize_t lid_wake_mode_set(struct device *dev,
147                                  struct device_attribute *attr,
148                                  const char *buf, size_t count)
149 {
150         int i;
151         for (i = 0; i < ARRAY_SIZE(lid_wake_mode_names); i++) {
152                 const char *mode = lid_wake_mode_names[i];
153                 if (strlen(mode) != count || strncasecmp(mode, buf, count))
154                         continue;
155 
156                 lid_wake_mode = i;
157                 return count;
158         }
159         return -EINVAL;
160 }
161 static DEVICE_ATTR(lid_wake_mode, S_IWUSR | S_IRUGO, lid_wake_mode_show,
162                    lid_wake_mode_set);
163 
164 /*
165  * Process all items in the EC's SCI queue.
166  *
167  * This is handled in a workqueue because olpc_ec_cmd can be slow (and
168  * can even timeout).
169  *
170  * If propagate_events is false, the queue is drained without events being
171  * generated for the interrupts.
172  */
173 static void process_sci_queue(bool propagate_events)
174 {
175         int r;
176         u16 data;
177 
178         do {
179                 r = olpc_ec_sci_query(&data);
180                 if (r || !data)
181                         break;
182 
183                 pr_debug(PFX "SCI 0x%x received\n", data);
184 
185                 switch (data) {
186                 case EC_SCI_SRC_BATERR:
187                 case EC_SCI_SRC_BATSOC:
188                 case EC_SCI_SRC_BATTERY:
189                 case EC_SCI_SRC_BATCRIT:
190                         battery_status_changed();
191                         break;
192                 case EC_SCI_SRC_ACPWR:
193                         ac_status_changed();
194                         break;
195                 }
196 
197                 if (data == EC_SCI_SRC_EBOOK && propagate_events)
198                         send_ebook_state();
199         } while (data);
200 
201         if (r)
202                 pr_err(PFX "Failed to clear SCI queue");
203 }
204 
205 static void process_sci_queue_work(struct work_struct *work)
206 {
207         process_sci_queue(true);
208 }
209 
210 static DECLARE_WORK(sci_work, process_sci_queue_work);
211 
212 static irqreturn_t xo1_sci_intr(int irq, void *dev_id)
213 {
214         struct platform_device *pdev = dev_id;
215         u32 sts;
216         u32 gpe;
217 
218         sts = inl(acpi_base + CS5536_PM1_STS);
219         outl(sts | 0xffff, acpi_base + CS5536_PM1_STS);
220 
221         gpe = inl(acpi_base + CS5536_PM_GPE0_STS);
222         outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);
223 
224         dev_dbg(&pdev->dev, "sts %x gpe %x\n", sts, gpe);
225 
226         if (sts & CS5536_PWRBTN_FLAG) {
227                 if (!(sts & CS5536_WAK_FLAG)) {
228                         /* Only report power button input when it was pressed
229                          * during regular operation (as opposed to when it
230                          * was used to wake the system). */
231                         input_report_key(power_button_idev, KEY_POWER, 1);
232                         input_sync(power_button_idev);
233                         input_report_key(power_button_idev, KEY_POWER, 0);
234                         input_sync(power_button_idev);
235                 }
236                 /* Report the wakeup event in all cases. */
237                 pm_wakeup_event(&power_button_idev->dev, 0);
238         }
239 
240         if ((sts & (CS5536_RTC_FLAG | CS5536_WAK_FLAG)) ==
241                         (CS5536_RTC_FLAG | CS5536_WAK_FLAG)) {
242                 /* When the system is woken by the RTC alarm, report the
243                  * event on the rtc device. */
244                 struct device *rtc = bus_find_device_by_name(
245                         &platform_bus_type, NULL, "rtc_cmos");
246                 if (rtc) {
247                         pm_wakeup_event(rtc, 0);
248                         put_device(rtc);
249                 }
250         }
251 
252         if (gpe & CS5536_GPIOM7_PME_FLAG) { /* EC GPIO */
253                 cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_NEGATIVE_EDGE_STS);
254                 schedule_work(&sci_work);
255         }
256 
257         cs5535_gpio_set(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_STS);
258         cs5535_gpio_set(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_STS);
259         detect_lid_state();
260         send_lid_state();
261 
262         return IRQ_HANDLED;
263 }
264 
265 static int xo1_sci_suspend(struct platform_device *pdev, pm_message_t state)
266 {
267         if (device_may_wakeup(&power_button_idev->dev))
268                 olpc_xo1_pm_wakeup_set(CS5536_PM_PWRBTN);
269         else
270                 olpc_xo1_pm_wakeup_clear(CS5536_PM_PWRBTN);
271 
272         if (device_may_wakeup(&ebook_switch_idev->dev))
273                 olpc_ec_wakeup_set(EC_SCI_SRC_EBOOK);
274         else
275                 olpc_ec_wakeup_clear(EC_SCI_SRC_EBOOK);
276 
277         if (!device_may_wakeup(&lid_switch_idev->dev)) {
278                 cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
279         } else if ((lid_open && lid_wake_mode == LID_WAKE_OPEN) ||
280                    (!lid_open && lid_wake_mode == LID_WAKE_CLOSE)) {
281                 flip_lid_inverter();
282 
283                 /* we may have just caused an event */
284                 cs5535_gpio_set(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_STS);
285                 cs5535_gpio_set(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_STS);
286 
287                 cs5535_gpio_set(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
288         }
289 
290         return 0;
291 }
292 
293 static int xo1_sci_resume(struct platform_device *pdev)
294 {
295         /*
296          * We don't know what may have happened while we were asleep.
297          * Reestablish our lid setup so we're sure to catch all transitions.
298          */
299         detect_lid_state();
300         send_lid_state();
301         cs5535_gpio_set(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
302 
303         /* Enable all EC events */
304         olpc_ec_mask_write(EC_SCI_SRC_ALL);
305 
306         /* Power/battery status might have changed too */
307         battery_status_changed();
308         ac_status_changed();
309         return 0;
310 }
311 
312 static int setup_sci_interrupt(struct platform_device *pdev)
313 {
314         u32 lo, hi;
315         u32 sts;
316         int r;
317 
318         rdmsr(0x51400020, lo, hi);
319         sci_irq = (lo >> 20) & 15;
320 
321         if (sci_irq) {
322                 dev_info(&pdev->dev, "SCI is mapped to IRQ %d\n", sci_irq);
323         } else {
324                 /* Zero means masked */
325                 dev_info(&pdev->dev, "SCI unmapped. Mapping to IRQ 3\n");
326                 sci_irq = 3;
327                 lo |= 0x00300000;
328                 wrmsrl(0x51400020, lo);
329         }
330 
331         /* Select level triggered in PIC */
332         if (sci_irq < 8) {
333                 lo = inb(CS5536_PIC_INT_SEL1);
334                 lo |= 1 << sci_irq;
335                 outb(lo, CS5536_PIC_INT_SEL1);
336         } else {
337                 lo = inb(CS5536_PIC_INT_SEL2);
338                 lo |= 1 << (sci_irq - 8);
339                 outb(lo, CS5536_PIC_INT_SEL2);
340         }
341 
342         /* Enable interesting SCI events, and clear pending interrupts */
343         sts = inl(acpi_base + CS5536_PM1_STS);
344         outl(((CS5536_PM_PWRBTN | CS5536_PM_RTC) << 16) | 0xffff,
345              acpi_base + CS5536_PM1_STS);
346 
347         r = request_irq(sci_irq, xo1_sci_intr, 0, DRV_NAME, pdev);
348         if (r)
349                 dev_err(&pdev->dev, "can't request interrupt\n");
350 
351         return r;
352 }
353 
354 static int setup_ec_sci(void)
355 {
356         int r;
357 
358         r = gpio_request(OLPC_GPIO_ECSCI, "OLPC-ECSCI");
359         if (r)
360                 return r;
361 
362         gpio_direction_input(OLPC_GPIO_ECSCI);
363 
364         /* Clear pending EC SCI events */
365         cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_NEGATIVE_EDGE_STS);
366         cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_POSITIVE_EDGE_STS);
367 
368         /*
369          * Enable EC SCI events, and map them to both a PME and the SCI
370          * interrupt.
371          *
372          * Ordinarily, in addition to functioning as GPIOs, Geode GPIOs can
373          * be mapped to regular interrupts *or* Geode-specific Power
374          * Management Events (PMEs) - events that bring the system out of
375          * suspend. In this case, we want both of those things - the system
376          * wakeup, *and* the ability to get an interrupt when an event occurs.
377          *
378          * To achieve this, we map the GPIO to a PME, and then we use one
379          * of the many generic knobs on the CS5535 PIC to additionally map the
380          * PME to the regular SCI interrupt line.
381          */
382         cs5535_gpio_set(OLPC_GPIO_ECSCI, GPIO_EVENTS_ENABLE);
383 
384         /* Set the SCI to cause a PME event on group 7 */
385         cs5535_gpio_setup_event(OLPC_GPIO_ECSCI, 7, 1);
386 
387         /* And have group 7 also fire the SCI interrupt */
388         cs5535_pic_unreqz_select_high(7, sci_irq);
389 
390         return 0;
391 }
392 
393 static void free_ec_sci(void)
394 {
395         gpio_free(OLPC_GPIO_ECSCI);
396 }
397 
398 static int setup_lid_events(void)
399 {
400         int r;
401 
402         r = gpio_request(OLPC_GPIO_LID, "OLPC-LID");
403         if (r)
404                 return r;
405 
406         gpio_direction_input(OLPC_GPIO_LID);
407 
408         cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_INPUT_INVERT);
409         lid_inverted = 0;
410 
411         /* Clear edge detection and event enable for now */
412         cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
413         cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_EN);
414         cs5535_gpio_clear(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_EN);
415         cs5535_gpio_set(OLPC_GPIO_LID, GPIO_NEGATIVE_EDGE_STS);
416         cs5535_gpio_set(OLPC_GPIO_LID, GPIO_POSITIVE_EDGE_STS);
417 
418         /* Set the LID to cause an PME event on group 6 */
419         cs5535_gpio_setup_event(OLPC_GPIO_LID, 6, 1);
420 
421         /* Set PME group 6 to fire the SCI interrupt */
422         cs5535_gpio_set_irq(6, sci_irq);
423 
424         /* Enable the event */
425         cs5535_gpio_set(OLPC_GPIO_LID, GPIO_EVENTS_ENABLE);
426 
427         return 0;
428 }
429 
430 static void free_lid_events(void)
431 {
432         gpio_free(OLPC_GPIO_LID);
433 }
434 
435 static int setup_power_button(struct platform_device *pdev)
436 {
437         int r;
438 
439         power_button_idev = input_allocate_device();
440         if (!power_button_idev)
441                 return -ENOMEM;
442 
443         power_button_idev->name = "Power Button";
444         power_button_idev->phys = DRV_NAME "/input0";
445         set_bit(EV_KEY, power_button_idev->evbit);
446         set_bit(KEY_POWER, power_button_idev->keybit);
447 
448         power_button_idev->dev.parent = &pdev->dev;
449         device_init_wakeup(&power_button_idev->dev, 1);
450 
451         r = input_register_device(power_button_idev);
452         if (r) {
453                 dev_err(&pdev->dev, "failed to register power button: %d\n", r);
454                 input_free_device(power_button_idev);
455         }
456 
457         return r;
458 }
459 
460 static void free_power_button(void)
461 {
462         input_unregister_device(power_button_idev);
463 }
464 
465 static int setup_ebook_switch(struct platform_device *pdev)
466 {
467         int r;
468 
469         ebook_switch_idev = input_allocate_device();
470         if (!ebook_switch_idev)
471                 return -ENOMEM;
472 
473         ebook_switch_idev->name = "EBook Switch";
474         ebook_switch_idev->phys = DRV_NAME "/input1";
475         set_bit(EV_SW, ebook_switch_idev->evbit);
476         set_bit(SW_TABLET_MODE, ebook_switch_idev->swbit);
477 
478         ebook_switch_idev->dev.parent = &pdev->dev;
479         device_set_wakeup_capable(&ebook_switch_idev->dev, true);
480 
481         r = input_register_device(ebook_switch_idev);
482         if (r) {
483                 dev_err(&pdev->dev, "failed to register ebook switch: %d\n", r);
484                 input_free_device(ebook_switch_idev);
485         }
486 
487         return r;
488 }
489 
490 static void free_ebook_switch(void)
491 {
492         input_unregister_device(ebook_switch_idev);
493 }
494 
495 static int setup_lid_switch(struct platform_device *pdev)
496 {
497         int r;
498 
499         lid_switch_idev = input_allocate_device();
500         if (!lid_switch_idev)
501                 return -ENOMEM;
502 
503         lid_switch_idev->name = "Lid Switch";
504         lid_switch_idev->phys = DRV_NAME "/input2";
505         set_bit(EV_SW, lid_switch_idev->evbit);
506         set_bit(SW_LID, lid_switch_idev->swbit);
507 
508         lid_switch_idev->dev.parent = &pdev->dev;
509         device_set_wakeup_capable(&lid_switch_idev->dev, true);
510 
511         r = input_register_device(lid_switch_idev);
512         if (r) {
513                 dev_err(&pdev->dev, "failed to register lid switch: %d\n", r);
514                 goto err_register;
515         }
516 
517         r = device_create_file(&lid_switch_idev->dev, &dev_attr_lid_wake_mode);
518         if (r) {
519                 dev_err(&pdev->dev, "failed to create wake mode attr: %d\n", r);
520                 goto err_create_attr;
521         }
522 
523         return 0;
524 
525 err_create_attr:
526         input_unregister_device(lid_switch_idev);
527         lid_switch_idev = NULL;
528 err_register:
529         input_free_device(lid_switch_idev);
530         return r;
531 }
532 
533 static void free_lid_switch(void)
534 {
535         device_remove_file(&lid_switch_idev->dev, &dev_attr_lid_wake_mode);
536         input_unregister_device(lid_switch_idev);
537 }
538 
539 static int xo1_sci_probe(struct platform_device *pdev)
540 {
541         struct resource *res;
542         int r;
543 
544         /* don't run on non-XOs */
545         if (!machine_is_olpc())
546                 return -ENODEV;
547 
548         r = mfd_cell_enable(pdev);
549         if (r)
550                 return r;
551 
552         res = platform_get_resource(pdev, IORESOURCE_IO, 0);
553         if (!res) {
554                 dev_err(&pdev->dev, "can't fetch device resource info\n");
555                 return -EIO;
556         }
557         acpi_base = res->start;
558 
559         r = setup_power_button(pdev);
560         if (r)
561                 return r;
562 
563         r = setup_ebook_switch(pdev);
564         if (r)
565                 goto err_ebook;
566 
567         r = setup_lid_switch(pdev);
568         if (r)
569                 goto err_lid;
570 
571         r = setup_lid_events();
572         if (r)
573                 goto err_lidevt;
574 
575         r = setup_ec_sci();
576         if (r)
577                 goto err_ecsci;
578 
579         /* Enable PME generation for EC-generated events */
580         outl(CS5536_GPIOM6_PME_EN | CS5536_GPIOM7_PME_EN,
581                 acpi_base + CS5536_PM_GPE0_EN);
582 
583         /* Clear pending events */
584         outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);
585         process_sci_queue(false);
586 
587         /* Initial sync */
588         send_ebook_state();
589         detect_lid_state();
590         send_lid_state();
591 
592         r = setup_sci_interrupt(pdev);
593         if (r)
594                 goto err_sci;
595 
596         /* Enable all EC events */
597         olpc_ec_mask_write(EC_SCI_SRC_ALL);
598 
599         return r;
600 
601 err_sci:
602         free_ec_sci();
603 err_ecsci:
604         free_lid_events();
605 err_lidevt:
606         free_lid_switch();
607 err_lid:
608         free_ebook_switch();
609 err_ebook:
610         free_power_button();
611         return r;
612 }
613 
614 static int xo1_sci_remove(struct platform_device *pdev)
615 {
616         mfd_cell_disable(pdev);
617         free_irq(sci_irq, pdev);
618         cancel_work_sync(&sci_work);
619         free_ec_sci();
620         free_lid_events();
621         free_lid_switch();
622         free_ebook_switch();
623         free_power_button();
624         acpi_base = 0;
625         return 0;
626 }
627 
628 static struct platform_driver xo1_sci_driver = {
629         .driver = {
630                 .name = "olpc-xo1-sci-acpi",
631         },
632         .probe = xo1_sci_probe,
633         .remove = xo1_sci_remove,
634         .suspend = xo1_sci_suspend,
635         .resume = xo1_sci_resume,
636 };
637 
638 static int __init xo1_sci_init(void)
639 {
640         return platform_driver_register(&xo1_sci_driver);
641 }
642 arch_initcall(xo1_sci_init);
643 

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